American  Society  of  Municipal 

/  » 

Improvements,  1915 

SPECIFICATIONS  FOR 

Stone  Block  Paving 

ADOPTED  OCTOBER  14,  1915 


These  specifications  will  be  modified  from  time  to  time 
to  keep  them  fully  up  to  date.     Suggestions  as  to 
modifications   or    additions   are    solicited   and 
should  be  sent  to  the  Secretary,  or  to  H.  H. 
Schmidt,    Chief   Engineer    Bureau   of 
Highway,  Brooklyn,  N.  Y.,  Chair- 
man  of  the    Sub-Committee 
on  Specifications  for  Stone 
Block  Paving,  and — 


GEORGE      W.     TILLSON 

Boro  Hall,  Brooklyn,  New  York 
Chairman  of  General  Committee  on  Standard  Specifications 


COPYRIGHTED,  1916 

Any  municipality  which  is  represented  in  the  membership  of  the  Society  by  one  or  more 
city  officials,  will  be  given  free  permission  to  use  these  specifications  or  any 
part  of  them  upon  application  to  the  Secre»a:y 


PUBLISHED  BY  THE  SOCIETY 
CHARLES  CARROLL  BROWN,  Secretary 


702  WULSIN  BUILDING 
INDIANAPOLIS,   INDIANA 


SPECIFICATIONS  FOR  STONE  BLOCK  PAVING. 
NEW  GRANITE  PAVING  BLOCKS. 

1.  The  paving  blocks  shall  be  of  medium  grained  granite,  show- 
ing an  even  distribution  of  constituent  minerals,  of  uniform  quality 
structure  and   texture,  without  seams,   scales  or  disintegration,   free 
from  an  excess  of  mica  or   feldspar,   and  equal   in  every  respect   to 
the  sample  in  the  office  of  the  engineer. 

TESTS. 

For  heavy  traffic  the  granite  shall  have  a  toughness  of  not  less 
than  nine  (9)  and  a  "French  Co-efficient  of  Wear"  of  not  less  than 
eleven  (11).  For  medium  traffic,  the  granite  may  have  a  toughness 
of  not  less  than  seven  (7)  and  a  "French  Co-efficient  of  Wear"  of 
not  less  than  eight  (8)  if  a  cement  grout  filler  is  used. 

The  above  tests  shall  be  made  by  the  methods  described  in  Bulletin 
No.  44,  U.  S.  Department  of  Agriculture,  Office  of  Public  Roads. 

The  average  of  three  (3)  tests  shall  be  used  for  determining 
toughness  and  the  average  of  six  (6)  tests  for  determining  the 
"French  Co-efficient  of  Wear." 

CERTIFICATES  AND  SAMPLES. 

2.  Contractors  shall  file  with  the  engineer  at  or  before  the  time 
of  bidding,  a  certificate  showing  the  name  and  location  of  the  quarry 
from  which  it  is  proposed  to  obtain  the  blocks,  also  a  certified  copy 
of   a    report    from    the    United    States    Department   of   Agriculture, 
showing  the   toughness   and   "French   Co-efficient  of  Wear"   of   the 
granite  which  it  is  proposed   to  use. 

On  or  before  the  date  of  the  letting,  six  (6)  specification  blocks, 
made  from  the  granite  it  is  proposed  to  use,  shall  be  filed  with  the 
engineer. 

3.  The  blocks  shall  be  of  the  following  dimensions:     Not  less 
than  eight   (8)   nor  more  than  twelve   (12)   inches  long  on  top;  not 
less  than  three  and  one-half  (3^)  nor  more  than  four  and  one-half 

inches  wide  on  top;   not   less   than   four  and   three-quarters 
nor  more  than  five  and  one-quarter   (5%)   inches  deep. 


342934 


The  blocks  shall  be  so  dressed  that  the  faces  will  be  approximately 
rectangular  in  shape,  and  the  ends  and  sides  sufficiently  smooth  to 
permit  the  blocks  to  be  laid  with  joints  not  exceeding  one-half  (^>) 
inch  in  width  at  the  top,  and  for  one  ( 1 )  inch  downward  therefrom, 
and  not  exceeding  one  ( 1 )  inch  in  width  at  any  other  part  of  the 
joint.  The  top  surface  of  the  block  shall  be  so  cut  that  there  will 
be  no  depressions  measuring  more  than  three-eighths  (^)  of  an 
inch  from  a  straight  edge  laid  in  any  direction  on  the  top  and  par- 
allel to  the  general  surface  thereof. 

Care  shall  be  exercised  in  handling  the  blocks,  so  that  the  edges 
and  corners  shall  not  be  chipped  or  broken,  as  blocks  otherwise  ac- 
ceptable may  be  rejected  on  account  of  spawling. 

4.  The   blocks   shall   be  sorted   and   laid    in   courses  of   uniform 
width,  except  in  special  cases,  as  may  be  ordered. 

NEW  SANDSTONE  PAVING  BLOCKS. 

5.  The   paving   blocks   shall   be   of   sound,   hard   sandstone,    free 
from  clay,  seams,   or  defects  which  would   injure  them   for  paving 
purposes,  of  uniform  quality  and  texture,  and  equal  in  every  respect 
to  the  sample  in  the  office  of  the  engineer. 

The  blocks  shall  be  of  the  following  dimensions:  Not  less  than 
eight  (8)  nor  more  than  ten  (10)  inches  long  on  top;  not  less  than 
three  and  one-half  (3^)  nor  more  than  six  (6)  inches  wide  on  top; 
not  less  than  four  and  three-quarters  (4%)  nor  more  than  five  and 
one-quarter  (5^4)  inches  deep. 

RECUT  OR  REDRESSED  PAVING  BLOCKS. 

6.  When  the  use  of  blocks  recut  from  old  paving  blocks  is  per- 
mitted, such  blocks  must  comply  with  the  specifications  for  quality 
of  stone,  as  required  for  new  blocks.    The  dimensions  may  be  varied, 
depending  upon  the  size  of  the  old  blocks  which  are  to  be  redressed, 
and  the  character  of  the  pavement  which  it  is  sought  to  obtain. 

SUB-FOUNDATION. 

7.  Any   soft   or   spongy   material   below   the  sub-grade,   shall   be 
replaced   with   sand,   gravel,   or   other   material,   as   directed   by   the 
engineer,    and    thoroly    rammed    or    rolled.      When    such    extra    fill 
exceeds  five   (5)   cubic  yards,  payment  will  be  made  for  the  excess. 


Care  shall  be  taken  in  excavating  not  to  disturb  the  sub-founda- 
tion, except  where  necessary  to  remove  the  soft  or  spongy  material. 

The  entire  sub-foundation  shall  be  compact  and  hard,  and  the 
contractor  shall  be  required  to  ram  or  roll  it  thoroly  with  a  roller 
satisfactory  to  the  engineer. 

CONCRETE  BASE. 

8.  After  the  sub-foundation  has  been  prepared  to  the  satisfaction 
of  the  engineer,  a  concrete  foundation  six   (6)   inches  thick  shall  be 
laid  thereon.     The  concrete  shall  conform  to  the  A.  S.  M.  I.  speci- 
fications for  concrete  for  pavement  foundations. 

The  grading  and  sub-foundation  shall  be  completed  at  least  fifty 
(50)  feet  in  advance  of  the  laying  of  concrete. 

CUSHION  COURSE. 

9.  On  the  concrete  base  shall  be  spread  a  layer,  averaging  one 
( 1 )   inch  in  depth,  of  clean,  coarse,  dry  sand,  free  from  all  gravel 
exceeding  one-quarter    ( *4 )    inch  in  size.     Upon  this  sand  bed  the 
blocks  shall  be  laid  in  courses  at  right  angles  to  the  line  of  the  street, 
and  in  a  straight  line  from  curb  to  curb,  except  in  special  cases,  when 
they  shall  be  laid  at  such  an  angle  as  may  be  directed  by  the  engineer. 
The  blocks  shall  be  laid  as  closely  as  possible,  each  block  touching 
the   adjoining  one  on  sides  and  ends,   and   in    courses    of    uniform 
width.     All  joints  shall  be  broken  with  a  lap  of  at  least  three   (3) 
inches.     The  blocks  shall  not  be  laid  more  than  twenty-five    (25) 
feet  in  advance  of  the  ramming. 

FILLING  JOINTS. 

10.  The   following  specifications  A,   B,   or   C,  shall   govern   the 
use  of  —Gas-Tar  Pitch  (A)— Asphalt  (B)— or  Cement  Grout  (C), 
depending  upon  the  kind  of  filler  to  be  used  in  the  joints: 

A. — GAS-TAR  PITCH  FILLER. 

11.  Immediately    after    the    blocks    are    laid,    coarse,    hot    gravel 
shall  be  spread  over  the  surface,  and  shall  be  swept  into  the  joints  so  as 
to  fill  the  space  between  the  blocks  to  a  depth  not  exceeding  two  (2) 
inches  from  the  bottom. 


The  blocks  shall  then  be  rammed,  to  settle  and  compact  thoroly 
the  gravel  in  the  joints,  and  so  as  to  leave  no  blocks  above  or  below 
the  general  surface  of  the  finished  pavement. 

The  joints  shall  then  be  poured  one-half  full  with  the  gas-tar 
pitch  filler,  hereinafter  described,  and  shall  be  filled  immediately  to 
within  one-half  (^2)  inch  of  the  surface  with  hot  gravel  and  again 
poured  with  the  filler.  This  last  pouring  shall  fill  the  joints  flush 
with  the  surface  of  the  blocks  and  shall  be  followed  immediately 
with  a  sufficient  amount  of  hot  gravel  applied  at  the  joints  to  cover 
the  filler. 

The  gravel  shall  be  clean,  washed  gravel,  between  one-quarter 
04)  and  one-half  (^2)  inch  in  its  largest  dimension. 

The  gas-tar  pitch  shall  comply  with  the  following  requirements: 

(a)  It  shall  have   a  specific  gravity  between    1.23   and    1.33   at 
60  degrees  Fahr. 

(b)  It  shall  have  a  melting  point  between   110  and   125  degrees 
Fahr.,  determined  by  the  cube  method  in  water. 

(c)  It  shall   contain   not   less   than   twenty    (20)    per  cent,   nor 
more  than  thirty-five   (35)   per  cent  of  free  carbon  insoluble  in  hot 
benzol  or   chloroform. 

(d)  It  shall  contain  not  more  than  one-half    (l/>}    per  cent,  of 
inorganic  matter. 

(e)  It  shall  be  free  from  water. 

(f)  It  shall  have  a  ductility  of  not  less  than  sixty   (60)    centi- 
meters at  77  degrees  Fahr. 

The  gas-tar  pitch  filler  shall  be  used  on  the  work  at  a  temperature 
of  not  less  than  two  hundred  and  fifty  (250)  degrees  Fahr.  and  shall 
at  no  time  be  heated  above  three  hundred  and  twenty-five  (325) 
degrees  Fahr. 

It  shall  be  delivered  where  directed  by  the  engineer  at  least  one 
week  before  being  used,  to  allow  for  examination  and  analysis.  If 
shrinkage  of  the  filler  in  the  joints  occurs,  the  pouring  shall  be  con- 
tinued until  all  joints  remain  permanently  filled,  but  no  flushing  of 
the  pavement  will  be  permitted. 

In  applying  the  gravel  and  filler,  care  shall  be  taken 
that  the  pavers  are  closely  followed  by  the  filler  gang,  and  in 
no  case  shall  the  paving  be  left  over  night,  or  when  work  is  stopped, 


without  the  filling  of  the  joints  being  completed.  In  case  rain  stops 
the  filler  gang  before  its  work  is  finished,  the  joints  shall  be  protected 
by  the  use  of  tarpaulins,  or  other  means  to  keep  out  water.  Under 
no  circumstances  shall  the  filler  be  poured  into  wet  joints. 

B — ASPHALT  FILLER. 

12.  Immediately  after  the  blocks  are  laid,  coarse  hot  gravel  shall 
be  spread  over  the  surface  and  shall  be  swept  into  the  joints  so  as 
to  fill   the  space  between  the  blocks  to  a  depth  not  exceeding  two 
(2)    inches   from   the   bottom. 

The  blocks  shall  then  be  rammed  to  settle  and  compact  thoroly 
the  gravel  in  the  joints,  and  so  as  to  leave  no  blocks  above  or  below 
the  general  surface  of  the  finished  pavement. 

The  joints  shall  then  be  poured  one-half  full  with  the  asphalt 
filler  as  hereinafter  described,  and  shall  be  filled  immediately  to 
within  one-half  (l/2)  inch  of  the  surface  with  hot  gravel  and  again 
poured  with  the  filler.  This  last  pouring  shall  fill  the  joints  flush 
with  the  surface  of  the  blocks  and  shall  be  followed  immediately  with 
a  sufficient  amount  of  hot  gravel  applied  at  the  joints  to  cover  the 
filler. 

The  gravel  shall  be  clean,  washed  gravel  between  one-quarter 
(/4)  and  one-half  (J^)  inch  in  its  largest  dimension. 

13.  The  filler  shall   be  an   asphaltic  cement,   entirely   free   from 
coal  tar  or  any  product  of  coal  tar  distillation. 

It  shall  be  waterproof,  free  from  water  or  decomposition  products, 
shall  adhere  firmly  to  the  paving  stones,  and  shall  remain  ductile 
and  pliable  at  all  climatic  temperatures  to  which  it  may  be  sub- 
jected in  actual  use.  It  shall  not  run  in  the  joints  in  the  hottest 
temperature  of  summer,  nor  become  hard  or  brittle  through  the 
action  of  frost. 

The  asphalt  filler  shall  comply  with  the  following  requirements: 

(a)  It  shall  contain  not  less  than  99  per  cent  of  pure  bitumen 
soluble  in  carbon  bisulphide. 

(b)  Of  the  total  bitumen  soluble  in  carbon  bisulphide,  not  less 
than  98^2  per  cent  shall  be  soluble  in  carbon  tetrachloride. 

(c)  It  shall  have  a  penetration  of  not  less  than  13  at  32  degrees 
Fahr.,  when  tested  with  a  No.  2  needle  under  a  load  of  200  grams 
for  1  minute. 


(d)  It  shall  have  a  penetration  of  not  more  than  250  at   115 
degrees  Fahr.,  when   tested   with   a   No.   2   needle  under   a  load  of 
50  grams  for  5  seconds. 

(e)  It  shall  have  a  penetration  of  not  less  than  40   nor  more 
than  60  at  77  degrees  Fahr.,  when  tested  with  a  No.  2  needle  under 
a  weight  of   100  grams  for  5  seconds. 

(f)  It  shall  have   a  ductility  of  not  less  than   7  centimeters  at 
77    degrees   Fahr.,    the   rate   of   elongation   being   5    centimeters   per 
minute. 

It  shall  be  heated  on  the  wrork  to  a  temperature  of  not  less  than 
three  hundred  and  seventy-five  (375)  degrees  Fahr.,  nor  more  than 
four  hundred  and  twenty-five  (425)  degrees  Fahr.,  and  in  such 
quantities  as  will  allow  this  temperature  to  be  maintained  in  the 
kettle  during  progress  of  the  pouring.  No  cement  having  a  temper- 
ature less  than  three  hundred  and  seventy-five  (375)  degrees  Fahr., 
shall  be  used. 

It  shall  be  delivered,  where  directed  by  the  engineer,  at  least  one 
week  before  being  used,  to  allow  for  examination  and  analysis.  If 
shrinkage  of  the  filler  in  the  joints  occurs,  the  pouring  shall  be  con- 
tinued until  all  joints  remain  permanently  filled  but  no  flushing  of 
the  pavement  will  be  permitted. 

In  applying  the  gravel  and  filler,  care  shall  be  taken  that  the 
pavers  are  closely  followed  by  the  filler  gang,  and  in  no  case  shall 
the  paving  be  left  over  night,  or  when  work  is  stopped,  without  the 
filling  of  the  joints  being  completed.  In  case  rain  stops  the  filler 
gang  before  its  work  is  finished,  the  joints  shall  be  protected  by  tar- 
paulins or  other  means,  so  as  to  keep  out  water.  Under  no  circum- 
stances shall  the  filler  be  poured  into  wet  joints. 

C — CEMENT  GROUT  FILLER. 

14.  Immediately  after  the  blocks  are  laid,  they  shall  be  thoroly 
rammed  and  brought  to  an  even  and  true  surface. 

15.  After  the  pavement  has  been  brought  to  a  uniform  surface, 
Portland  cement  grout  shall  be  poured  into  the  joints  until  it  appears 
on  the  surface.    The  grout  shall  be  broomed  into  the  joints,  if  neces- 
sary to  fill  the  same,   and  the  operation  shall   be  continued   as  the 
grout  settles,  until  the  joints  are  thoroly  filled  flush  with  the  sur- 

6 


face  of  the  blocks.  Immediately  after  this,  the  entire  pavement  shall 
be  broomed  to  a  smooth  surface.  The  blocks  shall  be  wetted  imme- 
diately before  applying  the  grout. 

The  cement  grout  shall  be  composed  of  one  ( 1 )  part  of  Portland 
cement  and  one  ( 1 )  part  of  clean  sharp  sand.  The  cement  and  sand 
shall  be  thoroly  mixed  dry  and  sufficient  clean,  fresh  water  shall  be 
added  to  give  the  grout  proper  consistency. 

The  grout  shall  be  mixed  for  this  purpose,  either  in  a  machine 
mixer,  to  be  approved  by  the  engineer,  or  in  a  box  about  4  feet  8 
inches  long,  30  inches  wide  and  14  inches  deep,  resting  on  legs  of 
different  lengths,  so  that  the  mixture  will  readily  flow  to  one  corner 
of  the  box,  the  bottom  of  which  shall  be  about  3  inches  above  the 
pavement.  Particular  attention  is  called  to  the  importance  of  ascer- 
taining the  proportional  amount  of  water  to  be  used  with  the  mix- 
ture of  different  kinds  of  cement  and  sand  to  give  the  best  results, 
and  when  the  most  advantageous  proportions  have  been  ascertained, 
these  shall  be  used.  While  being  applied  to  the  joints  the  mixture 
in  the  box  shall  be  continuously  stirred.  One  such  box  shall  be 
provided  for  about  each  ten  feet  in  width  of  the  roadway. 

The  work  of  filling  shall  be  carried  forward  until  an  advance  area 
of  fifteen  or  twenty  yards  has  been  grouted,  when  the  same  force  and 
appliances  shall  be  used  to  regrout  the  same  space  in  a  like  manner. 

The  work  shall  be  kept  lightly  sprinkled  with  water  ahead  of  the 
sweepers,  to  avoid  a  possibility  of  causing  the  grouting  to  become  too 
thick  at  any  point.  To  insure  the  penetration  of  the  grout  into  the 
joints  of  the  pavement  a  squeegee  scraper  fifteen  to  eighteen  inches 
in  length  in  addition  to  the  brooms,  shall  be  used  upon  the  last 
application  of  the  grout. 

After  the  grout  between  the  joints  has  fully  subsided  and  the 
initial  set  is  taking  place,  the  whole  surface  shall  be  lightly  sprinkled 
with  water  and  the  surplus  grout  left  on  the  top  shall  be  swept  into 
the  joints,  bringing  them  up  flush  and  full.  After  the  grouting  is 
completed  and  a  sufficient  time  for  hardening  has  elapsed,  so  that 
a  coating  of  sand  will  not  absorb  moisture  from  the  cement  mixture, 
one-half  (y2)  inch  of  sand  shall  be  spread  over  the  whole  surface. 
In  case  the  work  is  subjected  to  the  direct  rays  of  the  sun,  an  occa- 
sional sprinkling  shall  be  given  for  two  or  three  days  to  dampen  the 
sand. 


After  the  grouting  is  completed,  the  street  shall  be  kept  closed 
and  no  carting  or  traffic  allowed  on  any  part  of  the  grouted  pave- 
ment until  at  least  seven  days  have  elapsed.  The  surface  of  the 
pavement  shall  be  kept  moist,  as  may  be  directed  by  the  engineer. 

Should  the  bond  between  the  blocks  become  broken  before  the 
work  is  accepted,  the  joints  shall  be  cleaned  out,  even  if  it  is  neces- 
sary to  take  up  and  relay  the  blocks.  Such  defective  work  shall  be 
regrouted  or  relaid  and  again  barricaded  as  previously  described. 

NOTE.  When  in  the  judgment  of  the  engineer,  a  shallower  block 
than  that  before  specified  is  deemed  desirable,  a  block  3^4  to  ^1A 
inches  wide  wide,  3^4  to  4*4  inches  deep,  and  7  to  1 1  inches  long, 
may  be  used,  provided,  the  granite  has  a  sufficiently  high  factor  of 
toughness  and  "French  Co-efficient  of  wear." 


" 


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